אוצר המדרשים (אייזנשטיין) עמוד קפה
תנו רבנן: בימי מלכות יון הרשעה גזרו על ישראל שכל מי שיש לו בריח בתוך ביתו יחקוק עליו שאין לשונאי ישראל חלק ונחלה באלוקי ישראל. מיד הלכו ישראל ועקרו בריחים שבבתיהם. ועוד גזרו שכל מי שיש לו שור יכתוב על קרנו שאין לשונאי ישראל חלק באלוקי ישראל, הלכו ישראל ומכרו שוריהם. ועוד גזרו עליהם שיהיו בועלין נשיהן נידות. הלכו ישראל ופרשו מנשיהן. ועוד גזרו שכל מי שנושא אישה תיבעל להגמון תחילה ואח"כ תחזור לבעלה. ונהגו בדבר הזה שלוש שנים ושמונה חודשים, עד שנישאת בתו של יוחנן כוהן גדול. כיוון שרצו להוליכה אצל אותו ההגמון, פרעה ראשה, וקרעה בגדיה, ועמדה ערומה בפני העם. מיד נתמלא יהודה ואחיו חימה עליה, ואמרו: הוציאוה לשרפה ואל יתגלה דבר זה למלכות מפני סכנת נפשות, שהעזה פניה להיות ערומה בפני כל העם הזה. אז אמרה לו: היאך אתבזה לפני אחי ורעי ולא אתבזה בעיני ערל וטמא שאתם רוצים למעול בי ולהוליך אותי לשכב אצלו? כיוון ששמע יהודה וחבריו כך, נועצו יחדיו להרוג ההגמון. מיד הלבישו הנערה בלבוש מלכות ועשו חופה של הדס מבית חשמונאי עד ביתו של הגמון, ובאין כל בעלי נבל וכינור ובעלי זמר, והיו מזמרים ומרקדים, עד שבאו לבית ההגמון
(and see the Kovetz Genuzot V. 1 pgs. 165- 168 for another version of this Midrash and the extensive discussion by N. Rabinowitz in his Binu Shenos Dor V' Dor)
From a historical perspective, this Midrash is exceedingly puzzling. There is no record of any decree of jus primae noctis among the Greeks (see section one of this article). Nor is this decree mentioned in the book of Judith which is the basis of this Midrash.
From L. Rabinowitz, "The study of Midrash" JQR, 58 pg. 154 ff. we have the following (footnotes not included except one- brackets mine):
We are not concerned, however, with the truth of these allegations insofar as they refer to the Middle Ages in Europe, but with the possibility of its having existed during the Talmudic period, and in that respect the undeniable fact is that it has entered massively both into the Halacha and the Aggada. The outstanding example of its halachic aspect is found in the Talmud.
The regulation is laid down in the Mishnah [Lekket.com had a fascinating article from the WCJS on the reason behind this decree based on one of the Qumranic documents. Unfortunately, the site doesn't seem to be functional at present- W.] that the marriage of virgins was to take place on Wednesdays, so that, if the bride-groom found that he had been deceived with regard to the virginity of his bride, he could have immediate recourse to the Beth Din which met regularly on Thursdays. This law was changed, and the day altered to Tuesday, the reason given being that it was to circumvent the custom of jus primae noctis by the prefect, (tafsar).
In the Jerusalem Talmud 48 the same reason is given for the institution of the custom that the wedding should take place in the house of the bride-groom. In the Aggada the references are more numerous. Halfway between Halacha and Aggada is the vague statement of the Talmud with regard to the Festival of Chanukah. To the general rule that women are exempt from the performance of such commandments as depend upon a specific time for their performance, 49 the Talmud makes three exceptions, the reading of the Megillah on Purim, 50 the Foul Cups on Passover, 51 and the Kindling of the Lights on Chanukah 52 and in all three cases the identical reason for the exception is given, "since they also were included in that miracle".
Wherein, however, lay the particular role which they played in the events leading up to Chanukah? Rashi explains, "The Greeks decreed that all betrothed virgins should be subjected to the jus primat noctis by the prefect, and the miracle was effected through a woman.
A late scholium to Megillat Ta'anit actually says that it was this decree which was the immediate cause of the raising of the standard of revolt by Mattathias [Cf. E. Brodt's post no. 3 here - W.], and it has even been suggested that there may be a vague but historic reference to it in the Book of Maccabees itself: 56-"And the rulers and elders groaned, the virgins and young men were made feeble, and the beauty of women was changed. Every bridegroom took up lamentation; she that was in the marriage chamber was in heaviness... and all the house of Jacob was clothed in shame".
In the purely Aggadic sphere there are two references. The one, in the name of R. Judah, purports to explain the difficult verse 57 "There were giants on the earth in those days, and after that, when the sons of the overlords 58 came in unto the daughters of men and they bare children unto them", to the effect that "when they prepared a woman for her husband, the overlord used to enter and have intercourse with her first". 59 The other is-Bethuel the father of Rebecca. Says the Yalkut, 60 "Bethuel was king of Aram Naharaim, and he used to exercise the jus primae noctis over every virgin and then hand her over to her husband". 61 To complete this portion of the picture it is convenient here to add that Bethuel is cast as the villain of the piece, as will be abundantly shown. There is no villainy of which he is incapable, from theft to murder to rape of his own daughter, albeit, according to one version, under threat of death. That his fell designs are not executed is due to no virtue on his part. Other circumstances intervene.
(Footnote: I have searched in vain for some authority for my idea that the basis of this interpretation lies in the name Bethuel, with its suggested connection with Bethulah, a virgin. It does not need overmuch Midrashic imagination to suggest that they regarded the name as conveying "Lord of the virgins". The nearest I have found is a statement ascribed to I. Levi in R.E.J. 30.220-23I that "it may have been derived from the Roman legend of Virginius". (J.E. loc. cit.) Certainly the male name Virginius is as suggestive as Bethuel, but I have so far failed to trace this legend of Virginius.) [Rabinowitz fails to note that the story of Judith takes place in a city known as "Bethulia" - W.]
The next scholar to write about this subject is Tal Ilan - Premarital Cohabitation in Ancient Judea: The Evidence of the Babatha Archive and the Mishnah (Ketubbot 1.4) , HTR 86:
This mishnah attests different matrimonial practices in Galilee and Judea and suggests that premarital cohabitation was sometimes practiced in Judea, but certainly not in Galilee. The Palestinian Talmud interprets the mishnah, obviously apologetically, by assigning the Judean practice of premarital cohabitation to the aftermath of the Bar Kokhbah revolt, as a result of the imposition of the jus primae noctis ("the right of the first night"). The contract from the Babatha archive predates the Bar Kokhbah revolt, however, and thus attests a Judean practice of premarital cohabitation that is not connected to the Roman decree. In the article I shall suggest two possible interpretations for this practice. I shall conclude by arguing that the jus primae noctis in Jewish sources belongs, as has been shown for all other instances of the motif, to folklore and not to history.
Some sources suggest that after the Bar Kokhbah revolt the Romans introduced in Palestine the jus primae noctis, namely, the right of the local governor to deflower all maidens entering wedlock.34 The Palestinian Tamud refers to this "event" when it deals with the mishnah on the husband's residing at his father-in-law's house
(Footnote 34: The date of the alleged event is subject to some controversy. For example, Samuel Krauss ("La fete de Hanoucca," REJ 30  37-43) dated it to the aftermath of the Jewish revolt in the days of the emperor Trajan (115-117 CE). On the other hand, Samuel Belkin (Philo and the Oral Law [Cambridge, MA: Harvard University Press, 1940] 246) saw in it one of the Antiochean decrees (168 BCE). The Bar Kokhban date, championed, among others, by Raphel Patai ("Jus Primae Noctis," Studies of the Center for Folklore Research 4  177-80), seems to me, on account of the word 'nt usually associated with the Bar Kokhbah revolt, to be the correct interpretation. )
This tradition connects the imposition of the jus primae noctis with the 'nr decrees, which are usually associated with the aftermath of the Bar Kokhbah revolt. As a result, the rabbis enacted an emergency measure (nMpn), which was intended to avert the danger of Jewish maidens' losing their virginity to Roman soldiers and possibly even conceiving by them. In such a case, the prospective couple was actually encouraged to practice sexual inter-course and cohabit out of wedlock in the very house of the bride's father. The quasi-historical justification for this Judean custom, the jus primae noctis, belongs, however, in my opinion, to the apologetics of the Galilean rabbis, because in the next sentence the talmudic commentators go on to claim that althought he destruction( '1n) was discontinued,t he custom was not. (y. Ketub. 1.5, 25c) This claim means that in Judea men and women continued to practice some sort of premarital cohabitation before the nuptials.
The Talmud then goes on to state that even the daughter-in-lawo f Rabbi Oshaiah entered (the bridal chamber) pregnant. (y. Ketub. 1.5, 25c) This indicates that these matrimonial practices were followed in families of the Judean rabbis themselves. The admission of the talmudic sources that the custom of cohabitation prior to marriage was not easy to uproot even when the conditions that had brought it about, namely, the jus primae noctis of the aftermath of the Bar Kokhbah revolt, ceased to exist, also proves, in my opinion, that the custom did not arise from these conditions. Salome Komais' marriage contract, which is dated to August 131 CE and suggests a similar reality of premarital cohabitation, predates the Hadrianic decrees by four years and severs all previously assumed connections between the two. We have now surveyed another form of rabbinic apologetics, one which argues that premarital cohabitation was only practiced in Judea under the extremely hazardous conditions brought about by the jus primae noctis imposed by the Romans in the aftermath of the Bar Kokhbah revolt.
..question has been tackled by Raphel Patai,37 who formulated a remarkable theory. He was well aware of the fact that all medieval literature that evokes the custom of jus primae noctis has been proven to be folkloristic and has no historical basis.38 On the whole, Patai abided by these conclusions. He argued, however, that a special case should be made for the talmudic sources describing the same sort of custom. He claimed that since all the sources that are now considered legend and depict the practice in Christian medieval Europe were composed much later than the period they propose to describe, it is acceptable to discard them. In Judea, on the contrary, in the aftermath of the Bar Kokhbah revolt, the Romans actually put into practice such a law, as the "reliable" rabbinic sources claim. Patai, as a folklorist, should have known better. If a motif of this sort could have appeared in a sixteenth-century document and upset the entire history of medieval Europe for the next two centuries, the same motif likewise could have cropped up in the fourth- or fifth-century Palestinian Talmud, falsely describing events of the second century.39 In my opinion, the conclusions of the present article, which make the jus primae noctis narrative of the Palestinian Talmud nothing more than an apology for an inconvenient Judaic custom that is described cryptically in the Mishnah, undermine Patai's claim.40 From a large repository of folkloristic material circulating worldwide, the jus primae noctis was conveniently drawn in order to explain and justify a custom that seemed to the rabbis to under-mine their view of proper conduct in Jewish society.
[W. - Ilan's thesis seems to me to be exaggerated. As one can see from the copious citations in Rabinowitz - jus primae noctis is a recurring motif in the Midrashic literature and can hardly be attributed solely to an "invention of the Rabbis to gloss over an inconvenient custom". One is inclined to wonder if the frequent appearance of this particular bit of folklore in countries that were very much under the yoke of the Roman Empire (Medieval Europe, Palestine - as opposed to Persia and Babylonia) is not in fact an inheritance from the Roman conquerors.]